Auto merge of #181 - faern:upgrade-core-foundation, r=jdm

Upgrade core foundation

This is a PR in a series of PRs originating at https://github.com/servo/core-foundation-rs/pull/132

The plan is to make a breaking change to `core-foundation` and release it as `0.5.0`. But before the merge/publish of `core-foundation` I will prepare a set of PRs making sure the entire dependency graph of Servo is ready for this change and can be switched over to `0.5.0` directly.

TODO before merge:
- [x] Merge `core-graphics` PR and publish.
- [x] Remove the last commit from this PR, so we depend on `core-foundation` from crates.io.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/cocoa-rs/181)
<!-- Reviewable:end -->

Cargo.toml

@@ -4,7 +4,7 @@ name = "cocoa"
 description = "Bindings to Cocoa for OS X"
 homepage = "https://github.com/servo/cocoa-rs"
 repository = "https://github.com/servo/cocoa-rs"
-version = "0.13.0"
+version = "0.14.0"
 authors = ["The Servo Project Developers"]
 license = "MIT / Apache-2.0"
 
@@ -16,5 +16,5 @@ crate-type = ["rlib"]
 block = "0.1"
 bitflags = "1.0"
 libc = "0.2"
-core-graphics = "0.12.1"
+core-graphics = "0.13"
 objc = "0.2"